I’ve seen this mentioned a few times already: people wondering why certain communities don’t show up in their instance. You need to first search for that community via the magnifying glass icon and type in “!communityname@instance.domain”
Notice the exclamation mark at the beginning. Might take a few seconds. This will teach your instance about the remote community.
Also at least one person need subscribe
This didn’t work for me on this instance. Can some communities choose not to participate or limit their import? I searched for !aviation@lemmy.ml and several others and nada.
This has been changed with the latest version of Lemmy. Try this link: /c/aviation@lemmy.ml and check over at lemmy.ml/instances to make sure your instance is not blocked. (It’s at the very bottom, I just checked for you and it doesn’t look like it).
Edit: your instance is using an older version. Searching should still work. Try a couple of times. Make sure the search page is /search and use no filters